The Duck debuts
The DUKW proved to be up to the task when transporting cargo and supplies. Photo supplied by Jim Gilmore. Courtesy: U.S. Marine Corps
After the Dec. 7, 1941 attack on Pearl Harbor and the United States’ subsequent entry into World War II, increased emphasis would be placed on amphibious warfare. The DUKW would be one of the most improbable success stories of the war.
The DUKW was the brainchild of yacht designer Rod Stephens Jr., British sailor Dennis Puleston, and ROTC Lieutenant Frank W. Speir, in cooperation with the National Defense Research Committee and the Office of Scientific Research and Development. DUKW is GMC’s nomenclature description. The D indicates the year the vehicle was designed (1942), U stands for Utility, K indicates all-wheel-drive and W indicates two powered rear axles. Looking at the name DUKW, however, soldiers could not help but use the term “Duck.”
The GMC division of General Motors, known as the Yellow Truck and Coach Co. before the war, was chosen to manufacture the first prototype in April 1942. The prototype was constructed around a GMC ACKWX cab over truck.
“Actually, the military approached Ford Motor Co. first, but they declined,” says Gilmore. “They were already heavily involved mass-producing the Jeep and, unlike GMC, did not have a 6x6 vehicle that could be quickly converted.”
A watertight rectangular hull with a curved bow was welded around the truck, with special attention paid to approach and departure angles. The installation of a propeller and rudder system would complete the amphibious transformation. It was 31 feet long, 8-and-a-quarter feet wide, and just under 9 feet tall.
The DUKW cab was equipped with a folding windshield and side extensions. There was room for the driver and co-driver in front on a plywood cab floor. It was powered by a 270-cubic-inch, 94-horsepower straight-6 engine with five forward gears and high-low range. The DUKW was able to reach speeds of 50 mph on land and 5.6 nautical mph at sea. A high-capacity bilge pump kept the vessel afloat in rough water, and it could carry over 2 tons payload or up to 12 troops, depending on equipment. There was no armament, but it was equipped with a mount for a .50-caliber Browning heavy machine gun.